In the first phase of the trial, patients suffering from chronic, acute migraine pain were given varying doses of a combined THC-CBD drug. Researchers found that patients receiving 200mg of the medication every day for three months reported a 55% reduction of chronic pain symptoms. Lower doses did not provide the same level of pain relief.

In the second trial phase, patients suffering from migraines were given either the THC-CBD drug or a dose of amitriptyline, an antidepressant commonly used to treat migraines. This phase of the trial also included participants suffering from cluster headaches, who were given either the cannabis medication or a dose of verapamil, a drug often prescribed to treat cluster headaches.

The study reported that the cannabis medication was very effective at reducing migraine pain, with patients reporting 43.5% less pain on average. The THC-CBD combo was also slightly more effective than amitriptyline at reducing the frequency of migraine attacks. The cannabis medication was effective at reducing pain symptoms of cluster headache sufferers, but only those who had migraines when they were children saw this benefit.

Patients taking the THC-CBD medication also reported fewer negative side effects than those taking the prescription meds. The patients who received cannabis reported fewer stomach aches and muscle pains, as well as fewer incidences of colitis. However, some of the cannabis patients did report feeling drowsy and having difficulty concentrating, which is understandable given the psychoactive nature of THC.